Drawing Energy from Wastewater

Energy managers have a new option that simultaneously addresses two vital issues: Energy efficiency and water treatment.

Water, in general, is increasingly important, and a topic that is closely tied to energy. Cambrian Innovation Founder and CEO Matt Silver told Energy Manager Today that treating wastewater consumes as much as 3 percent of the electricity used in the United States annually. “That’s a massive amount of energy,” Silver said. “The irony is that much of the wastewater that is treated contains energy. That is particularly the case for industrial wastewater.”

Clearly, updating wastewater treatment is a priority. The company’s flagship product, the EcoVolt Reactor, offers two great advantages, according to Silver: It drastically reduces the energy needed to clean wastewater and, in the process, generates high quality natural gas in the form of methane, which can be captured and used to power other processes. “We see a big opportunity for a solution that can not only eliminate the energy required to treat wastewater but also generates energy from the process,” Silver said.

Each EcoVolt Reactor module can generate 40KW of energy. Total system capacity – by linking modules – can approach 300 KW, Silver said. He estimates that an organization can generate as much as 20 percent of the operational energy it needs from the process. Carbon dioxide also is converted into methane, which leads to emission reductions. Silver said that an installation at The Lagunitas Brewing Company in Petaluma, CA has cut emissions by 1,200 metric tons.

Cambrian Innovation was founded in 2006 with funding from NASA, which must find innovative ways of providing clean water in space. The agency has not bought a system, however. The company has ten units in the field and three more under construction. The first went out the door in 2014, Silver said.

Today, Cambrian Innovation announced a partnership with the Russian River Brewing Company in Santa Rosa, CA for use of its EcoVolt MBR. Russian River will only use the water cleansing function for the time being. The water is potable, but not used for drinking or brewing. Energy generation capabilities, via the EcoVolt Reactor, will be added later.

Silver says that the company’s approach is feasible for more vertical industry segments than other aerobic or anaerobic systems because it can scale to smaller capacities and can use microbes that like to snack on a wider variety of wastewater. Return on investment (ROI) for such systems depends on many factors. Indeed, in some cases, ROI isn’t even a factor: Companies simply aren’t allowed to increase their water utilization. Thus, a system that adds efficiency is mission-critical.

The core of the system is the way in which impurities and pollutants are removed from water. Today’s approaches use pollutant-eating bacteria that are bubbled at very high rates through the contaminated water. The problem is that the bubbling – which is done at industrial strength – is an energy hog.

Cambrian Innovation uses the same basic science: Hungry bacteria eat pollutants and contaminants. The approach is anaerobic, however. The type of microbes used don’t need air to live. Therefore, their introduction into the contaminated isn’t based on high speed bubbling. Instead, the microbes find the pollutants that they want to have for dinner by an electromethanogenic processes.

Aerobic and anaerobic approaches are well known, Silver said. To date, anaerobic approaches have proven to be impractical. Two steps that that Cambrian Innovation has taken to commercialize the approach is to use unique microbes and to encase them in a film in the reactor through which the contaminated water is poured. This is a more effective approach than, essentially, dumping them into the tanks, Silver said.